Method of fixing toner applying wet medium

Abstract: Method of fixing toner by applying fixing agent to an object accomodating unfused toner at predetermined positions by sparaying or dripping onto the object, or immersing the object from back surface of the object. The fixing agent causes the unfused toner to be half-dissolved or swollen on the surface of the object and the half-dissolved or swollen toner is dried up to be fixed to the object.

Description: The present invention relates to an improved method of fixing tuner by applying wet medium. Conventionally, there are a variety of practical methods for fixing unfused toner on a paper surface after being transferred thereto from a photoconductor of a dry electronic copier or, a laser printer, for example, including the following: 1. Thermal fixing methods: [1] Thermoconductive method for fusing and fixing unfused toner with a heated roller; [2] Radiation method for fusing arid fixing unfused toner by radiating infra-red rays or flash; [3) Convection method for fusing arid fixing unfused toner via a heat treatment in an electric oven; [4) High-frequency thermal method for fusing and fixing unfused toner by heating water content of medium and objective paper in an electronic microwave oven; 2. Pressure fixing method for fusing and fixing unfused toner by applying pressure generated by a high-pressure roller: 3. Wet fixing method for fusing and fixing unfused toner by dissolving thermoplastic resin (being a constituent of toner) with solvent via solvent atmosphere. However, the above conventional fixing methods respectively have a variety of technical problems described below. When applying any of the thermal fixing methods, unfused toner cannot properly be fixed onto all the objective surfaces except for those which are having specific sizes. Concretely, a proper heating means Is essential to implement the thermal fixing method. However, because of technically difficult aspect, large heating means cannot be applied. For instance, whenever drawing image on a large-sized paper such as the Al or A0 class, image must be drawn on the paper surface with ink of a slow-moving pen-plotter directly. On the other hand, since the above-cited pressure fixing method necessarily applies such a high pressure being more than scores of kilogram per square centimetre, operator is obliged to introduce large-sized equipment and soft-and-expensive resin such as polyethylene resin or polypropylene resin for composing toner, thus incurring too expensive processing cost. US 3383775, discloses a method of fixing a toner image on a substrate by hot vapour treatment with a fixing agent comprised of a two-phase mixture of water and an organic compound, which has toner swelling capacities and is insoluble in water. In GB-A-2026506, a powder mark is applied to a substrate and then fixed by applying a solvent. The powder comprises a soluble resin, a pigment and a solvent insoluble component which serves to assist in rapid drying of the solvent during fixing. In SU-A-589585, electrographic images are fixed by spraying a liquid solvent (e.g. water) onto paper carrying the developed image and then exposing the reverse side of the paper to the vapour of the solvent. Dyestuff dissolved in the solvent is precipitated near the surface. DE-A-1963785 discloses an immersion method and GB 1023052 discloses a back side impregnation method. In JP4036782, toner is transferred from a releasing agent coating sheet to a fibrous substrate, a resin component being dissolved with a fixing process agent. Another method including a supplementary transfer step is described in DE-A-3247177. The object of the invention is to fully solve the above problem by providing an improved method of fixing unfused toner onto objective surface of any size including large-size surface by applying wet medium at inexpensive cost without endangering environmental safety, thus securely fixing clear image fresh from the preceding transfer process. The invention provides a method of applying toner affixing wet medium as claimed in claim 1, 4 or 7. When implementing any of the first through third inventive methods, unfused toner is not fully dissolved on surface of the first objective, but instead, unfused toner may be first incompletely dissolved or swollen thereon. Next, half-dissolved or swollen toner surface is pressed against surface of second objective to cause the half-dissolved or swollen toner to be transferred onto the second objective before eventually drying the second objective. Fixing agent available for implementing the first through third inventive methods includes a fixing agent containing organic compound capable of half-dissolving or swelling toner, wherein the organic compound is dispersed and mixed in an organic compound incapable of dissolving or swelling toner. Next, functional operation of the invention is described below. According to the first inventive method, organic compound contained in fixing agent sprayed or dripped onto the surface of an objective such as paper does not fully dissolve the resinous component contained in the unfused toner at first, but instead, said organic compound transmutes the resinous component into half-dissolved or swollen condition (herein-after merely called gummy condition) to cause toner to closely adhere to surface of an objective for example. According to the second Inventive method, subsequent to the immersion of an objective superficially accommodating unfused toner in the prepared fixing-agent, organic compound contained in the fixing-agent transmutes resinous component in unfused toner into gummy condition to facilitate toner to closely adhere to the surface of the objective. Finally, after fully drying the toner coated objective, toner is firmly fixed on the surface thereof. According to the third inventive method, initially, an objective paper superficially accommodating unfused toner is impregnated with fixing-agent solution from the back surface thereof. Next, by causing the fixing agent to act upon the hack surface of unfused toner, organic compound in the fixing agent transmutes the resinous component contained in unfused toner into a gummy condition in order that the toner can closely adhere to the surface of the objective. After fully drying the objective, toner is solidly fixed on the surface of the objective. More particularly, when implementing any of the first through third inventive methods, dispersed mixing of such an organic compound capable of half-dissolving or swelling toner with such an organic compound incapable of dissolving or swelling toner merely results in transmutation of resinous component of toner into gummy condition without fully dissolving the resinous component by applying such a fixing agent capable of suppressing solubility of organic compounds. In consequence, toner is solidly fixed on the objective surface to generate clear-cut image. Furthermore, since unfused toner is first transmuted into gummy condition by applying fixing agent before securely being fixed on the objective surface, toner can easily be fixed without necessarily using a large sized thermal roller. According to another method, in the same way as was done for the first through third Inventive methods, unfused toner is first transmuted into gummy condition on the first objective surface, and then the second objective surface is superposed on the gummy toner. Next, the superposed second objective surface is pressurized to cause the gummy toner of the inverted image to be transferred onto the surface of the second objective. After fully drying the second objective, toner is firmly fixed on the surface of the second objective. The above and further objects and novel features of the invention will more fully be apparent from the following detailed description given in reference to the accompanying drawings which are shown below merely by way of example. BRIEF DESCRIPTION OF THE DRAWINGS Figs 1A and 1B schematically illustrate the first embodiment of the method of fixing toner by applying wet medium according to the invention; Figs 2A and 2B schematically illustrate the second embodiment of the method of fixing toner by applying wet medium according to the invention; Figs 3A and 3B schematically illustrate the third embodiment of the method of fixing toner by applying wet medium according to the invention; Figs 4A and 4B schematically illustrate the fourth embodiment of the method of fixing toner by applying wet medium according to the invention; Figs 5A and 5B schematically illustrate the fifth embodiment of the method of fixing toner by applying wet medium according to the invention; Figs 6A and 6B schematically illustrate the sixth embodiment of the method of fixing toner by applying wet medium according to the invention; and Fig. 7 is a sectional view of a conventional device for executing a conventional method of fixing toner by applying wet medium. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the accompanying drawings representing preferable embodiments, the method of fixing toner by applying wet medium according to the invention is described below. First Embodiment : As shown In Fig. 1A, using a sprayer 3, fixing agent 4 (based on formulary 9 shown later on) was initially sprayed onto surface of an objective paper 2 accommodating unfused toner 1 by a certain amount enough to prevent the unfused toner 4 from irregularly being stirred. As shown in Fig. 1B, after several seconds were past, the treated paper surface 2 was fully dried by blowing air via a blower 5. After completing the drying process, it was visually confirmed that toner 6 was fully fixed on the paper surface 2 without incurring blurred symptom to the produced image at all. Second Embodiment: As shown in Fig. 2A, initially, an objective paper 2 accommodating unfused toner 1 was conveyed through a "TEFLON"-coated non-adhesive sponge roller 7 and a receptive roller 8 and then damped with fixing agent 4 (based on formulary 1 shown later on) impregnated in the sponge roller 7. Next, after half-dissolving or swelling resinous component in the unfused toner 1, the resinous component was closely fixed on the objective paper surface 2. Finally, as shown in Fig. 2B, the paper 2 superficially adhered with gummy toner 1a was conveyed through a pair of thermal rollers 9 and 9 before fully being dried. After completing the drying process, it was visually confirmed that toner 6 was fully fixed on the paper surface 2 without incurring blurred symptom to the produced image at all. In Fig. 2A, the numeral 71 indicates a blade. Third Embodiment: As shown in Fig. 3A, a sponge roller 10 impregnated with fixing agent 4 (based on formulary 2 shown later on) was pressed against the back surface of an objective paper 2 superficially accommodating unfused toner 1 to fully impregnate the paper 2 with the fixing agent 4. Next, unfused toner 1 on the paper surface was damped with the fixing agent 4, and then, after swelling resinous component contained in the unfused toner 1, the swollen resinous component was closely fixed on the paper surface 2. Finally, as shown in Fig. 3B, the treated paper 2 was fully dried by pressing a heated plate 12 against the back surface of the treated paper 2. After completing the drying process, it was visually confirmed that toner 6 was fully fixed on the paper surface 2 without incurring blurred symptom to the produced image at all. The reference numeral 11 shown in Fig. 3A designates a sucking roller that fully absorbs surplus of the fixing agent 4. Fourth Embodiment: As shown in Fig. 4A, fixing agent 4 (based on formulary 4 shown later on) was dripped onto unfused toner 1 previously disposed on surface of an objective paper 2. As shown in Fig. 48, after several seconds were past, the treated paper 2 was dried in an oven 13. After completing the drying process, it was visually confirmed that toner 6 was fully fixed on the paper surface 2 without incurring blurred symptom to the produced image at all. Fifth Embodiment: As shown in Fig. 5A, initially, an objective paper 2 superficialy accommodating unfused toner 1 was immersed in a container 14 containing fixing solution 4 (based on formulary 9 shown later on). Then, after several seconds were past, the treated paper 2 was drawn out of the container 14, and finally, as shown in Fig. 5B, the treated paper 2 was fully dried in an oven 13. After completing the drying process, it was visually confirmed that toner 6 was fully fixed on the paper surface 2 without incurring blurred symptom to the produced image at all. Sixth Embodiment: As was done for the first embodiment, initially, using fixing solution 4, unfused toner 1 was converted into gummy condition, and then, gummy toner was almost closely fixed on a paper 2 serving as the first object. Next, as shown in Fig. 6A, the second objective paper 16 was pressed against the gummy toner la before being pressed by a pressing roller 15. As shown in Fig. 6B, the first objective paper 2 was then stripped off. As a result, toner la was transferred onto the surface of the second objective paper 16 in the inverted condition. Then, as shown in Fig. 1B, the second objective paper 16 was dried by blowing air from a blower 5. After completing the drying process, it was visually confirmed that toner 6 was fully fixed on the image inverted onto the second objective paper 16 without causing the image to incur blurred symptom. It should be understood however that practical method of fixing toner onto an objective paper via application of wet medium according to the invention is not solely restricted to those embodiments exemplified above. For example, when implementing the third embodiment, the fixing-agent solution 4 immersedly permeates into the paper 2 from the back surface by pressing the sponge 10 against the back surface of thepaper 2. In place of the pressing method, solution of the fixing agent 4 may also be sprayed against the back surface of the paper 2. When implementing the above embodiments, thermal drying process was solely applied. However, air drying process, decompressed drying process or conventional drying process under normal temperature may also be applied. When implementing the sixth embodiment, a paper served as the other object of fixing toner. However, toner may also be transferred onto a wall surface for example. There is no limit in the kind of organic compound, in other words, in the kind of organic solvent capable of half-dissolving or swelling toner and yet being insoluble or hardly soluble to water. In order to prepare fixing agent for implementing the fixing method related to the invention, there is at least one kind of compound selectable from a group of those which are exemplified below; organic ester compound, organic hydrocarbon compound, fatty-acid compound, organic ketone compound, halogenated hydrocarbon compound, aldehyde compound, ether compound, heterocyclic compound, alcoholic compound, organic nitrogen compound, and at least one kind of compound selectable from a group comprising derivatives from any of the above-exemplified compounds. Any of the above-exemplified organic compounds may not necessarily be of liquified form. For example, solid organic compounds may be dissolved in organic solvent. In terms of organic ester compound, any of those which are exemplified below may be selected for treating toner with the method related to the invention, for example, including the following,- those aliphatic ester compounds such as ethyl acetate, ethyl oleate, ethyl acrylate, ethyl methacrylate, dibutyl succinate, dimethyl adipate, diethyl adipate, dimethyl succinate, diethyl succinate, dimethyl glutarate, diethyl glutarate, diethyl phthalate, dibutyl phthalate, diethyl tartarate, butyl palmitate, dioctyl phthalate, ethyl α aminoate, or ethyl L-glutarate, and derivatives from the above aliphatic ester compounds; those aromatic ester compounds such as methyl benzoate or triphenyl phosphate and derivatives from these aromatic ester compounds, heterocyclic ester compound such as methyl isonicotinate and derivative from it. In terms of organic hydrocarbon compound, any of those which are exemplified below may be used for treating toner with the method related to the invention, for example, Including the following; kerosine, fluid paraffine, heptane, benzene, toluene, or cyclohexane, etc. In terms of halogenated hydrocarbon compound, 1,1, 1-trichloro- ethane or α-chloronaphthalene may be used for implementing the method of fixing toner related to the invention. In terms of alcoholic compounds, the following may be used for treating toner related to the invention; methanol; ethanol, n-octyl alcohol, n-decyl alcohol, diethylene glycol, glycerine, polyethylene glycohol, methyl cellosolve, tertiary amil-alcohol, phenol, benzyl alcohol, or methyl benzyl alcohol, etc. In terms of acidic compound, those which are cited below may be used for treating toner with the method related to the invention, for example, including the following; acetic acid, benzoic acid, alkenic succinic acid, naphthenic acid, oleic acid, or isononanic acid, etc. In terms of ketone compound, acetone, methyl ethyl ketone, or methylisobutyl ketone, may be used for treating toner with the method related to the invention. In terms of aldehyde compound, acetoaldehyde or benzaldehyde may be used for treating toner with the method related to the invention. In terms of ether compound, ethyl ether, di isopropylether, or octylphenylether may be used for treating toner with the method related to the invention. In terms of organic nitrogen compound, N,N-dimethylformaldehyde, diethylamine, aniline, or dichlorohexylamine, may be used for treating toner with the method related to the invent ion. In terms of heterocyclic compound, N-methyl-2-pyrolydon may be used for treating toner with the method related to the invention. Any kind of water such as pure water, distilled water, conventional tap-water, or river water, may be used. There is no specific restriction on the blend ratio between the above-exemplified organic compound and water. However, It Is desired that 1 through 90% by-weight of selected organic compound be contained in the fixing-agent solution against water. Preferably, the blend ratio shall remain in a range expressed by a formula shown below: α + 10/(100 - β) - 10 through (100 - β)/β + 10 where α designates limit (% by weight) of solubility of organic compoundagainst water, whereas β designates limit (% by weight) of solubility of water against organic compound. In addition to any of those organic compounds exemplified above and water, available fixing agent may also contain any of those surface active agents exemplified below; higher aliphatic-acid metal salt such as sodium laurate or sodium oleate, anionic surface active agent such as sodium alkylbenzenesulphonate, higher alcohol (sodium lauryl sulfate, sodium cetyl sulfate, or sodium stearyl sulfate, for example); cationic surface active agent falling under quaternary ammonium salt or amine sakt; and those nonionic surface active agents including alkylene-oxide (ethylene oxide or propylene oxide)- added type nonionic surface active agents such as higher alcohol (lauryl alcohol, cetyl alcohol, palm-oil reduced alcohol, oleic alcohol), alkyl (octic, nonyl, or dodecyl) phenol, or aliphatic acid (stearic acid or oleic acid), or those nonionic surface active agents falling under polyhydric alcohol ester such as sorbitol or sugar ester, for example. Normally, it is desired that 1 part or more than 1 part by weight of any of those usable surface active agents be added against 100 parts by weight of the blend of organic compound and water. Although practical effect of fixing toner based on the inventive method can be achieved even when no surfactant is added to the fixing-agent solution, it is essential that selected organic compound be properly mixed with water before starting off the toner fixing process by sufficiently vibrating and stirring the blend solution. When implementing the inventive method by formulating usable fixing-agent solution, it is suggested to properly blend an optimum amount of selected surfactant with a predetermined amount of mixed solution of selected organic compound and water if deemed necessary. It is suggested that selected assisting agent conventionally called "coupling agent' may also be added to toner-fixing agent, for example, including the following; cellosolves such as diethylene glycol, triethylene glycol, polyethylene glycol, monobutyl ether, diethylene glycol monomethylether, and diethylene glycol monobutylether, or N- methyl-2-pyrolydon, or the like. When using any of those assisting agents, dispersibility of organic compound is promoted, thus eventually improving toner-fixation effect and simultaneouosly saving consumption of surface active agent as well. No restriction applies to the toner fixing agent in which such an organic compound capable of dissolving or swelling toner is dispersedly mixed in another organic compound incapable of dissolving or swelling toner. To materialize such an organic compound capable of dissolving or swelling toner, it is suggested that dibasic carbonicacid diester be used. To materialize the other organic compound incapable of dissolving or swelling toner, propylene carbonate is suggestsed for use. No restriction applies to formulary of a fixing agent in the present invention but the following formularies are suggested. Formulary A dibasic carboxylic diester (dimethyl adipate 17wt%, dimethyl glutarate 66wt%, dimethyl succinate 17wt%) 20wt% propylene carbonate 80wt% Formulary B dibasic carboxylic diester (dimethyl adipate 17wt%, dimethyl glutarate 66wt%, dimethyl succinate 17wt%) 30wt% propylene carbonate 70wt% Formulary C dibasic carboxylic diester (dimethyl adipate 17wt%, dimethyl glutarate 66wt%, dimethyl succinate 17wt%) 40wt% propylene carbonate 60wt% Formulary D dibasic carboxylic diester (dimethyl adipate 17wt%, dimethyl glutarate 66wt%, dimethyl succinate 17wt%) 60wt% propylene carbonate 40wt% Formulary E dibasic carboxylic diester (dimethyl adipate 17wt%, dimethyl glutarate 66wt%, dimethyl succinate 17wt%) 50wt% propylene carbonate 40wt% sodium sulfate of butyl oleate 10wt% Formulary F dibasic carboxylic diester (dimethyl adipate 17wt%, dimethyl glutarate 66wt%, dimethyl succinate 17wt%) 50wt% propylene carbonate 40wt% 3 methyl-3 methoxybutanol 10wt% In terms of resin used for toner, it is suggested to employ polyethylene resin, polypropylene resin, polyacryl resin or polyester resin. Further, wood, resin, ceramic or fabric may serve as an object of fixing toner, instead of paper.

Claims: A method of fixing toner by applying a wet medium comprising: half-dissolving or swelling toner by spraying or dripping fixing agent on the surface of an objective of fixing, accommodating unfused toner at a predetermined position, said fixing agent containing organic compound capable of half-dissolving or swelling toner, said organic compound being dispersed in an organic compound incapable of dissolving or swelling toner; and drying the objective of fixing. A method of fixing toner by applying a wet medium according to claim 1, further comprising after half-dissolving or swelling the toner on the surface of a first objective of fixing: pressing the half-dissolved or swollen toner against the surface of a second objective of fixing to cause the half-dissolved or swollen toner to be transferred onto the second objective of fixing; and drying the second objective of fixing. A method of fixing toner by applying a wet medium according to claim 1 or 2, wherein the organic compound capable of half-dissolving or swelling toner is a dibasic carboxylic diester and the organic compound incapable of dissolving or swelling toner is propylene carbonate. A method of fixing toner by applying a wet medium comprising: half-dissolving or swelling toner by immersing an objective of fixing accommodating unfused toner at a predetermined position in a fixing agent, said fixing agent containing organic compound capable of half-dissolving or swelling toner, said organic compound being dispersed in an organic compound incapable of dissolving or swelling toner; and drying the objective of fixing. A method of fixing toner by applying a wet medium according to claim 4, further comprising after half-dissolving or swelling the toner on the surface of a first objective of fixing: pressing the half- dissolved or swollen toner against the surface of a second objective of fixing to cause the half dissolved or swollen toner to be transferred onto the second objective of fixing ; and drying the second objective of fixing. A method of fixing toner by applying a wet medium according to claim 4 or 5, wherein the organic compound capable of half-dissolving or swelling toner is a dibasic carboxylic diester and the organic compound incapable of dissolving or swelling toner is propylene carbonate. A method of fixing toner by applying a wet medium comprising: half-dissolving or swelling toner by impregnating an objective of fixing with fixing agent from the back surface of the objective of fixing, accommodating unfused toner at a predetermined position, until the fixing agent reaches the toner, said fixing agent containing organic compound being capable of half-dissolving or swelling toner, said organic compound being dispersed in an organic compound incapable of dissolving or swelling toner; and drying the objective of fixing. A method of fixing toner by applying a wet medium according to claim 7, further comprising after half-dissolving or swelling the toner on the surface of a first objective of fixing: pressing the half-dissolved or swollen toner against the surface of a second objective Of fixing to cause the half-dissolved or swollen toner to be transferred onto the second objective of fixing; and drying the second objective of fixing. A method of fixing toner by applying a wet medium according to claim 7 or 8, wherein the organic compound capable of half-dissolving or swelling toner is a dibasic carboxylic diester and the organic compound incapable of dissolving or swelling toner is propylene carbonate.

Inventors: FUKAI HISAYO, FUKAI, HISAYO
Applicants: QYENTOS CORP, UNICO CO LTD, QYENTOS CORPORATION, UNICO CO. LTD.
Application year: 1994
Main classification: G03G11
IPC codes: G03G15, G03G11